ACIDITY IN DETERMINING SOUNDNESS OF CORN. 



41 



BELOW O 

 32 



PER CEA/T OF TOTAL SAMPLES. 



20 30 40 so eo 70 eo 



The monthly average acidity of corn considered damaged and the 

 monthly average acidity of corn considered sound, as separated from 

 samples representing approximately 3,000 cars received at a terminal 

 market, compare with the relation of the degree of acidity of corn to 

 its general appearance. (Fig. 31.) It will be seen that the corn 

 appearing sound to the eye was uniformly low in degree of acidity, 

 exceeding the limit 

 of 22 c. c. only 

 slightly in any of the 

 months. Attention 

 is also called to the 

 increase of acidity in 

 both the sound and 

 damaged corn 

 through the summer 

 months, until the ar- 

 rival upon the mar- 

 ket of the new crop. 



Of 127 samples of 

 corn selected for 

 seed, only three 

 showed a degree of 

 acidity above 22 c. c, 

 and these samples 

 showed evidence of 

 deteriorationthrough 

 their low germina- 

 tive power. (Fig. 

 10.) 



With a knowledge 

 of the fact that as 

 corn deteriorates the 

 degree of acidity in- 

 creases and from the 

 results of investiga- 

 tions as described in 

 the preceding para- 

 graphs, it is believed that 22 c. c. most closely denotes the first stages 

 in deterioration and that any corn showing a degree of acidity greater 

 than 22 c. c. is, by comparison, of lower quality and lacking in nor- 

 mal qualities of soundness which it at one time possessed. 



From the theoretical standpoint it is undoubtedly true that coin 

 with a degree of acidity of 15 c. c. more closely approximates ideal 

 quality and soundness than corn with an acidity of 20 c. c. It has 

 been the aim, however, in fixing the initial limit at 22 c. c. to choose 



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Fig. 30.— Curves showing the percentage of samples of corn in each 

 commercial grade tested for degree of acidity which fell below 15, 

 below 16. below 17, and so on up to and including 32 c. c, repre- 

 senting approximately 2,500 cars received at a principal terminal 

 market from December, 1911, to May, 1913, inclusive. 



